Five Principles for Responsible Outdoor Lighting
Too often, outdoor electric lighting installations at night are overlit, left on when not needed, and harmful to the environment. As a result, light pollution is a growing global issue that can negatively affect our environment and impact our quality of life. DarkSky and the Illuminating Engineering Society jointly published the Five Principles for Responsible Outdoor Lighting to prevent and reduce light pollution through the proper application of quality outdoor electric lighting.
By applying these principles, properly designed electric lighting at night can be beautiful, healthy, and functional. Projects that incorporate these principles will save energy and money, reduce light pollution, and minimize wildlife disruption.
Five Principles for Responsible Outdoor Lighting
If light is deemed useful and necessary, follow these guidelines to prevent, or when that’s not possible, minimize light pollution.
Responsible outdoor lighting is:
1. Useful
All light should have a clear purpose
Before installing or replacing a light, determine whether light is needed. Consider how the use of light will impact the area, including wildlife and the environment. Consider using reflective paints or self-luminous markers for signs, curbs, and steps to reduce the need for permanently installed outdoor lighting.
2. Targeted
Light should be directed only to where it’s needed
Use shielding and careful aiming to target the direction of the light beam so that it points downward and does not spill beyond where it is needed.
3. Low level
Illumination should be no higher than necessary
Use the lowest light level required. Be mindful of surface conditions, as some surfaces may reflect more light into the night sky than was intended.
4. Controlled
Light should be used only when it is useful
Use controls such as timers or motion detectors to ensure that light is available when it is needed, dimmed when possible, and turned off when not needed.
5. Warm-colored
Use warmer-color lights where possible
Limit the amount of shorter wavelength (blue-violet) light to the least amount needed. Light where you need it, when you need it, in the amount needed, and no more.
More
Learn more about Responsible outdoor lighting.
Read the original April 2020 Lighting Principles announcement (includes a Spanish language version).
Downloads
You’re free to download and distribute the Five Principles in unmodified form.
For printing
Postcard size (8.5″ x 5.5″ with bleeds + crop marks) (PDF)
Postcard size (8.5″ x 5.5″ without bleeds) (PDF)
^ Updated September 2023
For web, social
Web version (1400 x 904 px) (PNG)
^ Updated September 2023
Translations
English, Spanish, French, Mandarin, Arabic, Portuguese,
Polish, Swahili, Japanese, Slovenian, Italian, German,
Malay, Tamil.
